1. Technical Field
The present invention relates to a nitrogen-containing tricyclic compound useful as a medicine, a medicine containing the same and processes for producing the same. More particularly, it relates to a novel nitrogen-containing tricyclic compound useful as a medicine for diseases against which the effect of inhibiting the binding of IgE receptor .gamma. to a tyrosine kinase of 72 kDa is efficacious.
2. Prior Art
The bronchial asthma and the atopic diseases in human beings appear in consequence of highly intriacate vital reactions. It is suspected that most of these conditions are caused because various chemical mediators liberated from mast cells and basophils, as triggered by antigen-antibody reactions, induce vital disturbances as by contracting such smooth muscles as bronchial muscles and vessels of the pulmonary circulation or enhancing permeability of blood vessels.
As the chemical mediators liberated from mast cells and basophils, histamine, leukotrienes, prostaglandins, TNF, etc. have been known. It is well known that histamine, among other substances mentioned above, is the most significant chemical mediator for the allergic rhinitis and the urticaria in human beings. The leucotrienes comprise leucotrienes B.sub.4, C.sub.4, and D.sub.4 and the relation thereof with the asthmatic convulsion has been attracting attention.
Heretofore, the development of medicines for the prevention, alleviation, or elimination of the crisis of symptoms of allergic diseases has been aimed at repressing the creation and liberation of such chemical mediators or antagonizing the effects thereof.
Sodium cromoglycate (Intal.TM.) having been marketed since 1969 is a typical example of these drugs.
However, the conventional antiallergic agents typified by Intal.TM. show difference in the chemical mediator liberation inhibitory concentration between in vitro and in vivo. Moreover, sensitivities to these drugs widely vary from patient to patient and their action mechanisms still remain unknown in many points.
Mast cells and basophils closely relating to allergic diseases have a highly affinitive receptor, FcE.epsilon.RI, for the IgE antibody on the cell membrane thereof. IgE antibody's binding to this receptor forms a cross-linkage with the corresponding polyvalent antigen, the intracellular signal transmission mechanism is activated. Then histamine is liberated or leukotrienes and prostaglandins are formed and liberated, thus inducing the onset of the so-called allergic symptoms. It is further more considered that the cytokines such as TNF and interleukins thus produced interact with other cells and thus make the diseases chronic.
Under these circumstances, the present inventors have paid their attention to the activation of a non-receptor type tyrosine kinase located at the early stage in the activation of the intracellular signal transmission mechanism upon liberation of chemical mediators from mast cells or basophils. It is known that this tyrosine kinase is activated when it binds to the phosphorylated tyrosine activation motif (TAM) region in the IgE receptor .gamma. chain. By inhibiting this binding to thereby inhibit the activation of the tyrosine kinase of 72 kDa, the activation of the intracellular signal transmission mechanism depending on the IgE antibody in mast cells or basophils can be inhibited. As a result, also the liberation of the above chemical mediators can be inhibited. The present inventors have found out that desired objects can be achieved by using nitrogen-containing tricyclic compounds represented by the following formula (I), thus completing the present invention.